Cassette orientation detection apparatus

Abstract

A reversible film cassette is disclosed for use with a photographic device such as a microfilm camera. A microcontroller including semiconductor memory circuits and a power source are resident in a film cassette. When the cassette is operatively positioned in the host photographic device, interfacing means are provided for establishing a two-way communication path between the microcontroller in the cassette and a microprocessor, or computer in the photographic device. Interface means are provided on opposite sides of the cassette for establishing a first communication path between the cassette and the photographic device when the cassette is loaded into the device in a first orientation. A second communication path is established when the cassette is loaded into the device in a second orientation. The microcontroller within the film cassette can determine the orientation of the cassette in the photographic device by determining on which path the communications occurred. The microcontroller within the cassette having information concerning the mode of filming being used, can then determine if the cassette orientation is correct.

We claim: 
     
       1. In a reversible film cassette adapted to be loaded in either of two positions into a photographic device having means for advancing film in said cassette in one direction relative to said photographic device to expose successive areas of said film in said cassette, said cassette including, a housing, a film supply reel and take-up reel, a film strip connected to said reels at opposite ends thereof with the major portion of said film initially wound upon supply reel, the proper exposure of said film being effected by first loading said cassette into said photographic device in a first orientation in which the film therein is transferred by said film advancing means from said supply reel to said take-up reel and, after substantially all of said film has been so transferred, reloading said cassette into said photographic device in a second orientation in which the film therein is then transferred from said take-up reel back to said supply reel, the improvement comprising: electronic means including a source of electrical power in said cassette for receiving and generating communication signals; and   interface means on opposite sides of said cassette for establishing a first communication mode between said cassette and said device when said cassette is loaded into said device in said first orientation and for establishing a second communication mode between said cassette and said device when said cassette is loaded into said device in said second orientation, whereby the communication mode by which signals are communicated to said device is established by the orientation of the cassette.   
     
     
       2. The film cassette as set forth in claim 1 including electronic means in said photographic device responsive to said mode of communication established by the orientation of the cassette such that the device will control the movement of film within said cassette. 
     
     
       3. The film cassette as set forth in claim 1 wherein said interface means is an optical coupling between said cassette and said photographic device. 
     
     
       4. The film cassette interface means as set forth in claim 3 wherein said interface means further includes an emitter and detector pair at either side of said cassette such that one of said pairs is aligned with an emitter and detector pair in said photographic device when said cassette is loaded into said device. 
     
     
       5. In combination, a photographic device intended to expose film and a cassette containing film intended for use in said photographic device comprising: means providing for insertion of said cassette into said photographic device in one of two orientations with only one of said orientations being correct at any given time;   electronic communication interface means associated with said cassette and said photographic device allowing two-way communication between said cassette and said device;   logic means within said cassette for determining, as a result of said two-way communication, the actual orientation of said cassette and whether or not said determined orientation is correct and for generating an error signal in response to such determination.   
     
     
       6. The combination as set forth in claim 5 including means in said device responsive to said error signal for preventing movement of film in said cassette.